5-6 months - Start in February - In France, the construction sector is responsible for over 25% of greenhouse gas emissions (mainly due to the production of building materials) and 70% of national waste production (mainly excavated inert waste such as earth, gravel and concrete). The extraction of sand and gravel from quarries also generates large quantities of waste (washing sludge). In the face of the climate emergency, it is imperative to make far-reaching transitions by exploring the possibilities of adding value to these resources. Raw earth materials, whose virtues have been known for millennia, are low-carbon and reversible, and are enjoying a new lease of life. Combining raw earth and plant fibers increases the mechanical strength and reduces the density and thermal conductivity of these materials.